cytokeratin

1 9.3

A protein in skin and other body cells that helps them keep shape and shows cell type in tests

noun
/ˌsaɪtoʊˈkɛrətɪn/

Specialized

: citosqueratina

The epithelial component exhibited a positive immunohistochemical reaction to cytokeratin and a negative reaction to vimentin, whereas the mesenchymal component showed a positive immunohistochemical reaction to vimentin and a negative reaction to cytokeratin.
negative for cytokeratin
positive for cytokeratin
immunohistochemistry shows cytokeratin

Examples

The tumor cells were focally positive for synaptophysin and chromogranin but were negative for cytokeratin 7 and cytokeratin 5/6.

Academic text (2007)
Interestingly, MCC has both neuroendocrine features, such as neurofilaments and neuroendocrine granules, and epithelial features, such as cytokeratin in their cytoplasm.

Academic text (2007)
Immunohistochemistry was positive for cytokeratin and S-100 protein.

Academic text (2008)
Histochemical staining for cytokeratin was negative, but strongly positive for thyroglobulin.

Academic text (1998)
The tumor was immunonegative for S-100 protein, cytokeratin, and desmin.

Academic text (2006)
Immunohistochemical studies show a positive reaction with vimentin, but negative for desmin, S-100 protein, and cytokeratin.

Academic text (1996)
The reactions to epithelial membrane antigen (EMA) and cytokeratin were negative.

Academic text (2006)
Immunostains demonstrated that the tumor cells were positive for cytokeratin 20 with a characteristic paranuclear dot-like pattern (Figure 4).

Academic text (2007)
Immunohistochemical stains were positive for carcinoembryonic antigen (CEA) and low molecular weight cytokeratin.

Academic text (2007)
In laboratory tests, the pathologist looked for the presence of cytokeratin in the tissue samples to help identify the tumor type.

Surface Forms

cytokeratin singular

cytokeratins plural

Morphology

cytokeratin = keratin (semi-transparent) = cyto + keratin

The term is transparently built from the combining form 'cyto-' (cell) + 'keratin', but 'cyto-' is a specialised scientific morpheme.

Etymology

Cytokeratin comes from the parts cyto- 'cell' and keratin, the protein in hair and nails whose root means 'horn'. So cytokeratin is a 'horn-like' protein made in cells that helps give them structure and is often used in lab tests to identify cell types or tumors.